Browsing by Author "Senevirathna, J.D.M."

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    Assessment of Suspended Plastic Levels in Surface Water of Southern Coastal Belt in Sri Lanka
    (Uva Wellassa University of Sri Lanka, 2019-02) Athapaththu, A.M.A.I.K.; Athawuda, A.M.G.A.D.; Dias, P.C.B.; Abeygunawardana, A.P.; Senevirathna, J.D.M.; Thushari, G.G.N.; Liyanage, N.P.P.; Jayamanne, S.C.
    Plastic pollution is a growing concern all over the world including Sri Lanka due to serious negative consequences. Thus, current study focused on investigation of occurrence, quantification and spatial distribution of visually observed plastics and microplastics (MPs) in surface coastal water from 12 locations (Hikkaduwa, Gallefort, Dodanduwa, Unawatuna, Weligama, Mirissa, Dickwella, Tangalle, Polhena, Rekawa, Godawaya, Hambantota) as covering 3 districts of southern coastal zone in Sri Lanka during July-December 2018. Surface water samples were collected by towing neuston, manta net (380 µm) along surface layer parallel to the shoreline using repeated measures approach. The samples were passed through 4000 µm, 500 µm and 250 µm mesh sieves and residual MPs were subjected to Wet Peroxide Oxidation protocol. Visually observed plastics and recovered MPs were observed through Trinocular Microscope, enumerated for density and confirmed by hot needle test. MPs were further sorted according to the color and shape. As results revealed, all the coastal water in sampling sites were contaminated with plastic accumulation. Overall average density of macroplastics and mesoplastics were recorded as 3.32 and 3.37 items/m³. Sampling location had no significant effect (p>0.05) on total MPs density (average total MPs density: 18.06±11.45 items/m³). Plastic accumulation sources of the affected sites were identified as harbor operational activities, residential actions and recreational events. MP debris with 0.512.00 mm consists of >65% of total number of MPs, whereas maximum size of microscopic plastic in coastal water was 11.04 mm. Fibers were the most common MPs followed by films. Blue colored and Transparent MPs were the majority of plastic items in coastal water due to prevalence of above plastic categories used in the packaging, bottles and fishing gears. In summary, southern coastal water in Sri Lanka is polluted by plastic debris and pollution control programmes are recommended by this study.
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    Comparative Analysis of Morphological Characters of Blue Swimming Crab, Portuntis pelagicus (Linnaeus, 1758) Populations of Western and North-Western Regions in Sri Lank
    (Uva Wellassa University of Sri Lanka, 2018) Disnika, A.V.H.R.; Senevirathna, J.D.M.; Liyanage, N.P.P.; Jayamanne, S.C.
    The blue swimming crab, Portunus pelagicus, is abundant in indo-west pacific regions and extremely contributes for commercial fishery industry. In Sri Lanka, this species is typically found in Western, Northern, North-Western and NorthEastern Coasts. Morphological studies of P. pelagicus are important to identify population clusters and distribution patterns. Hence, this study was conducted to identify morphological variations of blue swimming crabs collected from Puttalum and Kalpitiya areas of the North-Western coastal region and the Negombo area of the Western coastal region. A Total of 240 individuals, 80 from each site were analyzed using twelve morphometric parameters. Standardized morphometric measurements were subjected to Discriminant Function Analysis (DFA) to observe intra-specific variations. According to the results, two discriminant functions were derived with 63.8% and 36.2% of variance for function I and 2 respectively, while function 1 was predicted as the strongest component (P < 0.05). The length to width ratio of the major cheliped merus (MEL/MEW=0.71) and ratio between carapace width (including 9th anterior-lateral tooth) to carapace length (CW2/CL-0.59) were identified as highly contributing parameters for function 1 and 2 respectively. The overlapped group plots suggested that there was no intra-specific morphological variability among three populations. Based on the results, it can be suggested that all three P. pelagicus groups are morphologically similar and consider as one population. The length-weight relationships of crabs in all three sites recorded negative allometric growth (b<3). However, results need to be confirmed using molecular data. Results of the current study provide basic information which could be utilized when constructing management plans on fisheries and conservation for this economically important carb species.
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    Comparison of Blue Swimming Crab, Portunus pelagicus (Linnaeus, 1758) populations from Batticaloa and Trincomalee areas in Sri Lanka using Morphometric Parameters
    (Uva Wellassa University of Sri Lanka, 2018) Soyza, W.A.D.; Senevirathna, J.D.M.; Liyanage, N.P.P.; Jayamanne, S.C.
    Western, Northern and Eastern areas of Sri Lanka are famous for blue swimming crab fishery. However, very limited studies have been carried out to identify their population structure. This study investigated the utility of morphological characters to differentiate Portunus pelagicus populations of two different areas in eastern province of Sri Lanka. Samples were collected from Batticaloa (n=46) and Trincomalee (n=46) waters throughout its known geographic range. Twelve morphometric characteristics were measured up to nearest 0.01 mm. Discriminant Function Analysis (DFA) was performed to analyze significant intra-specific variations of two populations using standardized morphometric characteristics. The derived single discriminant function was totally accounted for 100% variance (Wilks' Lambda=0.74, P<0.05). The carapace width to carapace length ratio (CW2/CL) was recorded the highest canonical discriminant function coefficient (0.89), thus CW2/CL was selected as the most suitable parameter for the predicted model. The two centroids derived by DFA were 0.59 and (-0.59) respectively for the Trincomalee and Batticaloa, and predict the separation of two groups. According to the plotted graph, minimal overlapping between two groups was observed with possible variation between two populations. Two different allometric coefficients (b) were recorded as 2.92 (closer to isometric growth) and 2.76 (negative allometric growth) for Trincomalee and Batticaloa populations respectively. Hence, the results suggest that there is a possibility of having two P. pelagicus stocks in the 2 sites of the eastern part of the island. Changes of prevailing environmental conditions and habitat are the factors that lead to morphological differences of two P. pelagicus populations. Finding of this study is important for implementations of site-specific sustainable fishery management programs. Further, population genetic studies are recommended to confirm the results of the present study.
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    Current Status of Coastal Debris Accumulation along Beach Ecosystems in Southern Province of Sri Lanka
    (Uva Wellassa University of Sri Lanka, 2020) Athapaththu, A.M.A.I.K.; Egodauyana, K.P.U.T.; Jayarathna, W.N.D.S.; Abeygunawardana, A.P.; Senevirathna, J.D.M.; Thushari, G.G.N.
    Coastal debris accumulation in coastal and marine ecosystems is considered one of the serious, the emerging environmental problem in several countries including Sri Lanka. This study aims to identify the current status of debris accumulation in the coastal zone of Southern province in Sri Lanka. The 180 stakeholders were interviewed to collect data using a pre-tested questionnaire survey through 15 open-ended and rank order closedended questions (maximum 1-10 of scale) as a convenience sampling method. Based on the estimated median rank data, the majority of waste types were plastic (991.5), followed by glass (819.5) and papers (768.5) in the Southern coastal zone. Soft drink/water bottles (1264) were recorded as the major disposal items followed by food wrappings (1225) and Styrofoam food containers (1146) considering rank scores. Burning or collecting wastes (32.09%), handing over the garbage to the municipal council (25.5%), usage of public garbage bins (25.11%) are common waste disposal methods along the southern coast. The highest percentage of waste separation practices were recorded from Hikkaduwa (81.81%), Galle fort (60%), and Polhena (61.11%) regions. Hambantota and Tangalle beaches have regular waste collection services (100%) to a satisfactory level. Rekawa and Godawaya regional coasts had not recorded any frequent waste collection mechanism. Tourism and recreational activities (86.36-52.94%) and fisheries and harbor operations (93.33-60%) are major waste accumulation sources in study sites. Coastal debris is also accumulated by residential and household activities and unsustainable constructions to a lesser extent. Thus, unsustainable anthropogenic activities are major sources of coastal debris accumulation. The majority of fishermen and coastal residents did not adequately aware of the ecological and commercial impacts of coastal debris. This study suggests implementing integrated coastal management programs focusing on plastic debris accumulating sources. In conclusion, this study provides a basic platform on the issue of coastal debris deposition on the southern coast of Sri Lanka. Keywords: Plastic pollution, Coastal debris accumulation, Coastal environment, Pollution sources, Anthropogenic activities
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    Detecting Mislabelling of Packaged Frozen Seafood Products in Sri Lanka: A DNA Barcoding Approach
    (Uva Wellassa University of Sri Lanka, 2018) Perera, A.G.D.M.; Amarakoon, A.A.D.G.U.; Herath, D.R.; Senevirathna, J.D.M.; Liyanage, N.P.P.
    Seafood trade has conquered a vast market in global, as well as the local context. Substitution of high value species with those of low cost has become an emerging problem for the expanding market, since some of the products are visually unrecognizable and morphologically indistinguishable. The objective of this study was to assess the suitability of DNA barcoding as a method for species identification of packaged seafood to detect any mislabelling. Eight packaged frozen seafood product samples including finfish, crab, shrimp and cuttlefish were obtained from randomly selected supermarkets and subjected to DNA extraction by standard phenol chloroform DNA extraction protocol. Mitochondrial cytochrome oxidase subunit I gene (COI) was amplified in those samples with appropriate primers. Then successful five PCR products of tuna (T1 & T2), sailfish (SF1 & SF2) and crab (Cl) were selected for sequencing to build DNA barcodes. The prepared DNA sequences were compared with the Barcode of Life Database (BOLD) system for species identification. Close related sequences of each sample were downloaded from NCBI Genbank and phylogenetic trees were constructed using Maximum Parsimony, Maximum Likelihood and Neighbor Joining methods. Samples were identified as follows, T1 - Thunnus albacares (100%) and T2 Thunnus alalunga (99.85%), SF1 and SF2 - Istiophorus platypterus (100%) and Cl - Portunus pelagicus (97.71%). Identical tree topologies were resulted from three methods and three major clades were revealed in the phylogenetic tree as tuna, sailfish and crab groups. All selected five samples were matched (100%) showing that correct labelling had been done. This study concluded that DNA barcoding is a feasible, efficient and reproducible method for detection of mislabelling of packaged frozen seafood. However, the packaged frozen seafood trade has not reached high extent in Sri Lanka yet, hence substitution of seafood products does not occur frequently.
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    Effect of Solvent Type and Extraction Time on Yield and Purity of Lotus (Nelumbo nucifera)Leaf Wax
    (Uva Wellassa University of Sri Lanka, 2018) Prasadika, H.K.A.E.; Liyanage, N.P.P.; Pitawala, H.M.J.C.; Senevirathna, J.D.M.
    This study was conducted with the main objective of extracting lotus leaf wax using a simple methodology and to analyze the wax yield and purity of the extracted wax corresponding to different time treatments. Past studies have found that lotus plant leaf wax contains a mixture of aliphatic compounds mainly nonacosanol and nonacosanediols. Fresh, cleaned lotus leaves with 1 cm2 in surface area were exposed to three organic solvents (methanol, acetone and chloroform) and time taken for the presence of light green colour (due to the extraction of chlorophyll) in the medium was recorded to find out the most efficient organic solvent. Further, contact angle measurements of water drops placed on each of the leaf samples treated with different solvents were calculated to find out the efficiency of wax extraction. Based on the results obtained from this study leaf samples with surface area of 72.41 cm2 were exposed to chloroform by changing the dipping time duration ranging from two seconds to 30 minutes with time intervals of two seconds for the first five treatments ,15 seconds for the next three and five minutes for the last seven treatments. Extracted wax was subjected to the FTIR analysis to find out the purity of the wax. According to the results it was revealed that green colour was appeared in methanol within the first five minutes and there was no color change in the chloroform and acetone for about 30 minutes. Moreover, least change of the contact angle was shown by the leaf sample which was treated with acetone and it reveals that wax extraction was not done in an efficient manner. Chloroform is the best solvent to extract lotus leaf wax among three organic solvents used. The highest mean yield gives out by the time treatment with the dipping time of 20 minutes. And it shows that the purity decreases with the increase of the dipping time duration. Keywords
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    Freshness identification of marketable frigate tuna (Auxis thazard) using physical and chemical parameters under market storage conditions
    (Uva Wellassa University of Sri Lanka, 2018) Walpola, T.K.; Dias, P.C.S.; Senevirathna, J.D.M.; Liyanage, N.P.P.
    Identification of freshness of fish in the market is crucial for marine food fish industry in Sri Lanka. Chemical and physical qualities of fish are changed in storage condition and affected on the freshness level in fish muscle. This study was focused to examine chronological changes of physical and chemical parameters of frigate tuna to assess the freshness under the normal storage condition in the marketplace. Fish samples were collected from the commercial catch of Valaichchena harbor and stored under -18°C of freezing condition, which provided the normal market condition according to the findings of questionnaire survey. Five fish samples were kept at room temperature (~25°C) for 6 hrs in each day and pH value, alteration of water holding capacity, fat content, protein level and quality index of general appearance of fish species were tested daily after six hours of period for one week. Reference points of each parameter were suggested based on the pH changes of five replicates as pH act as key indicator on quality deterioration. The quality index of general appearance was ranged at minimum of zero (fresh) - maximum of 20 (spoiled). During the one week of storage period with the condition applied in the marketplace, pH value, water holding capacity, protein and fat content of frigate tuna were reduced significantly (p<0.05). Average pH value of frigate tuna was changed significantly at the 4th day (5.69±.045) (p<0.05), hence the 3rd storage day was considered as the reference point of quality deterioration of fish. At the 3rd day, water holding capacity, fat, protein content and quality index of general appearance were 72%, 0.8 c/o, 20% and 6.2 respectively. Fish appearance was highly changed at the 6th day of the period having 15.6 index value. This study recommends avoiding consumption of frigate tuna after three days in normal market storage condition and web based consumer guide would be useful to identify freshness of fish.
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    Occurrence of Microplastics in Gut and Muscles of Commerson's Anchovy in Madu-Ganga Estuary of Southern Province, Sri Lanka
    (Uva Wellassa University of Sri Lanka, 2020) Praboda, M.W.K.; Egodauyana, K.P.U.T.; Wijethunga, H.N.S.; Abeygunawardana, A.P.; Senevirathna, J.D.M.; Thushari, G.G.N.
    Plastic pollution causes serious ecological risks on biodiversity with toxicological effects on the biota. The objective of this study was to assess microplastic accumulation in seasonally common fishery resource: Stolephorus commersonnii (Commerson's Anchovy) harvested from Madu-ganga estuarine ecosystem. Fifteen matured fish samples (n=15) were randomly collected from local fishermen from November 2019 to January 2020. Microplastic particles were extracted from the digestive tract and muscles of anchovies using the recommended protocol of 10% KOH digestion. Hot needle test and Fourier Transform Infrared Radiation (FTIR) analysis were used for the confirmation of microscopically observed microplastics in anchovy samples. Microscopically observed microplastics were counted and categorized according to the size, color, and shape of plastics. Results revealed the microplastic accumulation in both the digestive tract and muscles of anchovies. Microplastics accumulate into the muscles via translocation and different respiratory modes. The average microplastic accumulation rate of anchovy gut and muscles were recorded as 301.70±3.58 items/g and 29.33±1.19 items/g respectively. White/transparent microplastic particles were the most abundant type in both guts (145.50±2.18 items/g) and muscles (13.55±1.23 items/g) of fish. However, blue (71.33+0.83 items/g: gut, 9.85+1.13 items/g: muscle), black (37.85+1.07 items/g: gut, 2.49+0.44 items/g: muscle), red (28.31+0.60 items/g: gut, 2.31+0.3 items/g: muscle) and pink (15.31+0.34 items/g: gut 0.96+0.24 items/g: muscle) microplastic debris were also recorded from gut and muscle samples. The majority of accumulated plastics in both gut and muscles were at the size range of 0.50 -1.00 mm. Fiber shape microplastics were observed in all the samples. FTIR results revealed that polypropylene as the only polymer type of microplastics in fish muscles and gut. This polymer is a key component of fishing ropes, netting materials, bottle caps, and packaging materials that enter through tourism/recreational activities and fishery operations into the estuarine ecosystem. Therefore, the current study recommends sustainable, integrated fishery management and eco-tourism programs focusing on plastic pollution control and prevention activities in Madu-ganga estuarine ecosystem. In conclusion, this study highlights the occurrence of microplastic contamination in the estuarine biota and the urgent need for plastic wastes management programs. Keywords: Coastal fishery resources, Estuarine ecosystem, Integrated fishery management, Microplastic accumulation rate, Plastic pollution control programmes
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    Preliminary study of Infectious Spleen and Kidney Necrosis Viral (ISKNV) disease in Asian sea bass (Lutes calcurifer) using histopathological method in Sri Lanka
    (Uva Wellassa University of Sri Lanka, 2018) Ekanayake, U.L.N.S.; Fouzi, M.N.M.; Wijesundera, R.R.M.K.K.; Senevirathna, J.D.M.; Kurukulasuriya, M.S.; Jayaweera, W.R.; Wanasinghe, W.M.L.A.; Sakajamary, V.
    Infectious Spleen and Kidney Necrosis Viral (ISKNV) disease is causing mass mortality in both marine and freshwater fish. Detection of this disease is crucial due to confusing clinical manifestations with many other bacterial and viral diseases. Pathology is one of the old and promising method for confirmatory diagnosis. The present study was carried out to confirm the presence of ISKNV in the cultured marine fish: Asian sea bass by histopathological method. Twenty moribund fish samples of sea bass with the mean weight of 60±20g were collected from cultured ponds in Trincomalee and Chillaw. Fish were selected based on the clinical signs suspected for ISKNV such as dark coloured fish with apathy, abnormal swimming, loss of appetite, pale gills and petechial hemorrhages in the operculum, mandible, fin base and abdomen. Spleen, Kidney, Liver, Gill and Brain samples were fixed in 10% neutral buffered formalin (NBF) for histopathological analysis. The formalinfixed tissues were processed routinely, embedded in paraffin wax, cut at 4 pm, and stained with Hematoxylin and Eosin (H&E). Postmortem finding of the study documented the presence of pale liver, pale gills, splenomegaly and fin rot. Degenerative and necrotic lesions in the kidney (mainly tubular epithelia) were observed in 15 fish (75%). Inflammatory cell (granulocytes, macrophages and lymphocytes) aggregates were observed in 10 fish (50%), while 17 fish (85%) showed degeneration, necrosis and vacuoles in hepatocytes with basophilic intracytoplasmic inclusion bodies. Inflammation of the gills were also observed in 10 fish (50%). This is the first study reporting the presence of ISKNV in the cultured marine fish: Asian Sea bass in Sri Lanka. Further studies are needed to determine the pathogenesis and pathology of ISKNV in different species of fish.
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    Screening of Plastic Pollution Effects in Madu-ganga Estuarine Ecosystem in Southern Province, Sri Lanka: An Approach toward the Coastal Zone Management
    (Uva Wellassa University of Sri Lanka, 2020) Praboda, M.W.K.; Wijethunga, H.N.S.; Silva, A.P.R.; Gayathry, D. L.; Abeygunawardana, A.P.; Senevirathna, J.D.M.; Thushari, G.G.N.
    Plastic pollutants act as the emerging contaminant with possible threats to aquatic ecosystems. The present study attempts to assess microplastic (MP) content in surface water and sediments of Madu-Ganga estuary which is one of the ecologically and commercially important Ramsar wetlands in Sri Lanka. Manta net (380 μm) was employed to collect surface water samples by towing net horizontally along water surface for 10 m with 1.8 ms-1 of average flow rate, while Ekman grab was used for sampling sediments from 4 study sites during October 2019 to January 2020. Wet Peroxide Oxidation (WPO) protocol was applied after subjecting both water and sediment samples to the wet sieving process. Fourier Transform Infrared Radiation (FTIR) analysis was used to confirm polymer types of extracted MPs in samples. MPs in digested samples were enumerated and categorized microscopically according to their size, shape, and color. One Way Analysis of Variance (ANOVA) was applied to identify the differences of MPs density with sampling location (p<0.05). According to the results, both surface water and sediment layers had contaminated by MPs accumulation. Sampling location had not significant (p>0.05) effect on the MP content of surface water and sediment samples. Average MPs accumulation rate of surface water and sediment samples were recorded as 40.06±1.84 items/m3 and 5.88±1.33 items/100g respectively. Whitetransparent, blue, black, and red were major color categories observed in MPs, while white-transparent color was dominant MP type of water and sediment samples. Most of the accumulated MPs were at the 0.50-1.00 mm of long-range. Fiber, sheet, and fragment shape MPs were commonly found in water and sediment samples. According to FTIR analysis, polypropylene (Characteristic absorption bands: 2950 cm−1 , 2915 cm− 1 , 2838 cm− 1 , 1455 cm− 1 , 1377 cm− 1 ) was abundant polymer type in surface water, while sediment contains polypropylene and polyvinyl chloride (Characteristic absorption bands: 1427 cm−1 , 1331 cm−1 , 1255 cm−1 ,1099 cm−1 , 966 cm−1 ). As per the preliminary survey, two major anthropogenic activities: commercial fishery and tourism were identified as the main point and non-point pollution sources in this ecosystem. In conclusion, this study emphasizes the growing risk of plastic pollution and the urgent need for a sustainable management plan to reduce plastic pollution in the Madu-Ganga estuary ecosystem. Keywords: Plastic contamination, Microplastics, Coastal ecosystem, Surface water, Benthic sediments, Anthropogenic factors
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    Screening the Effects of Microplastics on Selected Invertebrates along Southern Coastal Belt in Sri Lanka: A Preliminary Approach to Coastal Pollution Control
    (Uva Wellassa University of Sri Lanka, 2019-02) Wijethunga, H.N.S.; Athawuda, A.M.G.A.D; Dias, P.C.B; Abeygunawardana, A.P.; Senevirathna, J.D.M.; Thushari, G.G.N.; Liyanage, N.P.P.; Jayamanne, S.C.
    Primary and secondary microplastics entering into coastal and marine environment are potentially harmful to the health of aquatic organisms. Current study intended to assess plastic pollution effects on sessile invertebrates along the Southern coastal belt of Sri Lanka during July-December 2018. Twelve sampling sites (Hambantota, Godawaya, Rekawa, Tangalle, Dickwella, Polhena, Mirissa, Weligama, Unawatuna, Gallefort, Dodanduwa and Hikkaduwa) with different anthropogenic activities were selected as representing 03 districts (Hambantota, Matara, Galle) of Southern province. Biodiversity survey was conducted to identify prevalence of natural inhabitants in selected regional coasts and 03 dominant coastal mollusks: Saccostrea cucullata (Rock Oyster), Littorina sp. (Periwinkle) and Patella sp. (Limpets) were selected for screening microplastics accumulation level. Alkaline digestion protocol was identified as the most suitable procedure for microplastics extraction considering plastics recovery rate and digestion efficiency of flesh. Randomly collected, pooled biological samples (N=20-2) were subjected to KOH digestion and resultant microplastics were verified using hot needle test. As results revealed, all 03 invertebrates were contaminated with microplastics accumulation at average rates of 7.2-2.8counts/g in all sampling sites. Majority of contaminated microplastics were filamentous types (>90%) followed by rod shapes (1%). Microplastic accumulation rate varied significantly according to the type of species (p<0.05) due to differences of their feeding mechanism. Further, filter feeding organisms (Rock Oysters) were highly susceptible in accumulation of microplastics (7.24.1counts/g) in their bodies, while plastic accumulation rate was highest in oysters from Hambantota. Microplastic accumulation rate of mollusks was not significantly different according to the sampling site due to closer proximity (p>0.05). Tourism, unsustainable coastal fishery and harbor operational activities were identified as key factors affecting on higher plastic pollution level on Southern coast. Current study reflects negative aspect of plastic pollution on intertidal organisms.